1. Field of the Invention
The present invention relates to a projector installing device for making a projector pendant from a ceiling.
2. Description of the Related Art
When it is desired to install a projector on a ceiling, such a projector installing device as shown, e.g., in FIG. 10, has been used. In FIG. 10, a fixing member 20 fastened to a ceiling is made up of a ceiling plate 20A fastened to the ceiling by means of a plurality of bolts 21, a cylinder 20B downwardly projected from the ceiling plate 20A, and a mounting plate 20C fixedly secured to a lower end of the cylinder 20B. A pair of left and right brackets 23 of a projector 1 are fixedly secured to the mounting plate 20C by 4 screws 22 from their vertical direction, and the mounting plate 20C is formed therein with slots 20D for allowing rotation of the projector 1 around a vertical axis of the cylinder 20B relative to the mounting plate 20C.
After installing the projector 1 on the ceiling in the aforementioned manner, a worker conducts angle adjustment over the projector 1 in its left and right direction (horizontal direction). In this case, after loosing the 4 screws 22, the worker rotates the projector 1 within the slots 20D of the mounting plate 20C for the horizontal adjustment. After completing the horizontal adjustment, the worker again fixes the projector 1 to the mounting plate 20C by tightening the 4 screws 22 from their vertical direction.
As mentioned above, when it is desired to perform the angle adjustment over the projector 1 in the horizontal direction, not only the worker must loosen the 4 screws 22 from the vertical direction and then conduct the horizontal adjustment over the projector 1 with his posture changed, but also he must firmly securing the projector 1 to the mounting plate 20C by tightening the 4 screws 22 from the vertical direction with his posture again changed; which results in that the horizontal angle adjustment of the projector 1 is time-consuming. Further, since the full weight of the projector 1 is loaded to all the slots 20D of the mounting plate 20C through the 4 screws 22, there is a disadvantage that the worker cannot rotate the projector 1 smoothly, i.e., the adjusting operation is not easy. Furthermore, repetition of the horizontal angle adjustment of the projector 1 disadvantageously results in that the 4 screws 22 eventually become bent and the worker cannot conduct the adjusting work easily.